21413443 has 2 divisors, whose sum is σ = 21413444. Its totient is φ = 21413442.

The previous prime is 21413423. The next prime is 21413449. The reversal of 21413443 is 34431412.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21413443 is a prime.

It is a super-2 number, since 2×21413443² = 917071082228498, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21413449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10706721 + 10706722.

It is an arithmetic number, because the mean of its divisors is an integer number (10706722).

Almost surely, 2^21413443 is an apocalyptic number.

21413443 is a deficient number, since it is larger than the sum of its proper divisors (1).

21413443 is an equidigital number, since it uses as much as digits as its factorization.

21413443 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1152, while the sum is 22.

The square root of 21413443 is about 4627.4661533068. The cubic root of 21413443 is about 277.6912319834.

Adding to 21413443 its reverse (34431412), we get a palindrome (55844855).

The spelling of 21413443 in words is "twenty-one million, four hundred thirteen thousand, four hundred forty-three".